Electrical insulator



KALMAN VON KA'NDO.

ELECTRICRL INSULATOR.

APPLICATION FILED DECAL 1914.

1,376,486. Patented May 3, 1921.

IIIIIJIII" INVENTOR:

HZ/f; HIS ATT N EY IN FA T- UNITED STATES KALHAN VON KAINDO, OF VADO LIGURE, ITALY, ASSIGNOR, BY MESNE ASSTGNMENTS,

PATENT OFFICE.

TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, OF EAST PITTS- BURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

ELECTRICAL INSULATOR.

Specification of Letters Patent.

Patented May 3, 1921.

Application filed. December 9, 1914. Serial no. 876,382.

To all whom it may concern:

. Be it known that I, KALMAN VON KANDO, a subject of the Emperor of Austria and of the King of Hungary, and a resident of Vado Ligure, in the Kingdom of Italy, have invented a new and useful Improvement in Electrical Insulators, of which the follow-, in is a specification.

My invention relates to electrical insulators and in particular to insulators for supporting th contact wires of electric railwags.

ne object of my invention is to provide an improved means for anchoring a bolt strength and a high resistance. Porcelain,

by reason of its strength and superior insulating properties, is recommended as practically the best material for this purpose.

The low co-efiicient of expansion by heat of porcelain makes it difficult to secure the metal bolts which support the trolley conductors. Where cement is used for securing the bolts in porcelain insulators, a moderate rise in temperature produces sufficient expansion of the metal bolt and the cement to break the porcelain because the expansion of iron and of cement is many times as great as that of porcelain.

According to my invention I secure the metal bolt to the porcelain. insulator by means of an improved form of anchor embedded in an easily fusible metal. The porcelain is made substantially uniform in thickness and is inclosed by a metal shell having a restricted portion which is of smaller diameter than the body of metal in which the head of the bolt is embedded in order that th bolt cannot become disengaged from the metal shell and thereby release the contact wire from its support even though the porcelain should become broken.

Figure 1 of the accompanying drawing is a central sectional view of an insulator embodying my invention; Fig. 2 is a sectional view on the line IL-II of Fig. 1 and Fig. 3 is a plan view of the bolt-anchoring means shown in Fig. l.

The device shown in the drawing comprises a porcelain insulator 1, an improved anchor member 2, a conductor-suspending bolt 3 which is removably secured to the member 2, an interposed filling material 4 and a metallic casing 5.

The porcelain insulator l is of substantially bell-shape, has a constrained waist portion and is-illustrated as having walls of a uniform thickness. The anchor mem-- her 2, which is of elliptical form as best shown in Fig. 3, is sufiiciently narrow in one direction to b longitudinally admitted through the constrained opening of the porcelain 1 and has a diameter in another direction that is larger than the diameter of the opening through which it is admitted. A screw threaded aperture is provided in the center of the member 2 for suitably securing the same to'the bolt 3-. v

The filling material 4 is preferably a fusible alloy (such, for instance, as Roses metal) the melting point of which is Very low but still much above the maximum temperature likely to be experienced in practice and which contracts on solidifying. After solidification and cooling the mass of the parts2. 3 andv 4 contracts to a greater extent than the porcelain insulator Land, as a result, a space is formed between the mass 4 and the porcelain 1 which is sufiicient to permit of a free expansion of the parts 2, 3 and 4 without breaking the porcelam.

The metallic casing 5, by which the insulator may be readily suspended from strain wires or the like, is comprised of two parts which are secured together by the bolts 6. The space between the members .1 and 5 is filled with a cement 7 The casing 5 has a restricted portion 8, the opening in which is smaller than the mass, of securing metal 4, in order that the bolt 3 will not become disengaged from the metallic shell 5 and thereby release the contact wire from its support if the porcelain 1 should become broken. I

Toassemblesuch an insulator as I havedescribed, the anchor member 2' is first longitudinally inserted within the porcelain 1 and the bolt 3 is secured thereto. The space between the members 1 and 2 and 3 is then filled with the material 4. The two-piece casing 5 is positioned around the porcelain l and secured thereto by bolts 6 and an interposed layer of cement 7.

By employing the bell-shaped porcelain member shown in the drawing, the supporting bolt 3 may be of relatively large cross-section and short length which provides a very compact and strong insulator.

Although I have described my invention as embodied in a simple and preferred form of contact-wire insulator, it is not necessarily so limited and may be incorporated in a great many diflf'erent types of insulators.

I desire, therefore, that only such limita-' tions shall be imposed as are set forth in the appended claims. I claim as my invention:

1. The combination with a hollow insulator having a constricted opening, of an elliptical anchor member the larger diameter of which is greater than the largest diameter of the said opening, a bolt adapted to extend through said opening and be secured to said anchor member and filling material interposed between said insulator and said bolt and anchor member.

2. The combination with a hollow bellshaped insulator having a constricted opening, of an. elliptical anchor member that is adapted to be inserted through said opening and having the larger diameter thereof greater than the largest diameter of said opening, a bolt adapted to be secured to said anchor and filling material interposed between said anchor and said insulator.

3. The combination with a bell-shaped insulator having walls of a substantially uniform thickness and a constricted waist portion, of an elliptical anchor member adapted to be inserted only longitudinally within said insulator, a bolt extending into said, insulator and secured to said anchor member, a metallic casing surroundingthe upper portion of said insulator and secured thereto, and readily fusible metal surrounding said anchor member and said bolt and constituting a head for said bolt of larger diameter than the waist portion of said insulator. 7

4. The combination with a hollow bellshaped insulator having a restricted opening, a metallic casing surrounding the upper portion of said insulator and flaring out-.

upper portion thereof, of an elliptical anchor member adapted to be inserted only longitudinally within the upper portion of said insulator, a bolt adapted to be secured to said anchor member and an easily fusible metal for securing said anchorand said bolt within said insulator, the said body of fusi-- ble metal being of larger diameter than the waist of said insulator.

6. The combination with a hollow insulatorhaving a single constricted opening of circular form, of an anchor member. having one diameter. which is less than the d i anieter of said opening and another diameter which is greater than the diameter of said opening, a bolt adapted to extend through said opening and be secured to said anchor, and means for securing said bolt and anchor within said insulator.

In testimony whereof I have hereunto subscribed my name this 28th day of October, 1914.

KALMAN VON KANDO.

Witnesses:

C. A. JEVRABI, H. BORAGIM. 

